PENNSYLVANIAN [MISSOURIAN] OSTRACODES FROM THE CAMBRIDGE MEMBER, CONEMAUGH GROUP ON THE EASTERN LIMB OF THE BURNING SPRINGS ANTICLINE, RITCHIE COUNTY, WEST VIRGINIA

The Cambridge Member of the Glenshaw Formation (Conemaugh Group) on the eastern limb of the Burning Springs Anticline consists of 6.4 m (21 ft.) of light gray marine limestone and light gray mudstone. Twenty three samples of mudstone were collected (as continuous channel samples of successive 0.3 m [l.0 ft.] intervals) from just below to the top of the Cambridge. The samples were broken down via the kerosene method to study the microfossils present, specifically the ostracodes. Two genera of ostracodes, Cavellina and Moorites were found within this section, with Cavellina dominating (>99%) in the samples containing ostracodes. The specimens of Cavellina may represent two species. Many of the specimens of Cavellina are well preserved and articulated with abundant growth series (wide range of instar sizes) indicating minimum transportation of the shells. Very few other fossils were present in the samples except for a few internal molds of small gastropods; fragments of bivalves, bryozoans, crinoids, and brachiopods; and the agglutinated foraminifera Ammodiscus. The micritic limestones (with common productid brachiopods) within the Cambridge Member consist of three less than 0.3 m (1.0 ft) beds (over an interval of about 1.8 m [6 ft.]) in the lower portion of the Cambridge marine interval, each separated by gray mudstone. Based on the ostracodes and other microfossils, the Cambridge marine interval may represent a cyclothemic regressive phase above the Brush Creek Coal and Brush Creek Shale (dark gray to black marine shale). The lower portion of the Cambridge sequence may represent a fully marine nearshore environment, with the upper portion above the limestone beds (containing less abundant ostracodes and other microfossils) representing a nearshore marginal marine environment.